The present invention relates to a developing cartridge, a process cartridge and an electrophotographic image forming apparatus to which the process cartridge is mountable. The electrophotographic image forming apparatus forms an image on a recording material through an electrophotographic image-formation-type process. Examples of the electrophotographic image forming apparatus include an electrophotographic copying machine, an electrophotographic printer (a laser beam printer or an LED printer mountable), a facsimile machine, a word processor and the like. The process cartridge integrally contains an electrophotographic photosensitive drum, and charging means, developing means or cartridge, in the form of a unit or a cartridge, which is detachably mountable to a main assembly of an image forming apparatus. The process cartridge may contain the electrophotographic photosensitive drum, and at least one of charging means, developing means and cleaning means, in the form of a cartridge which is detachably mountable to the main assembly of the image forming apparatus. Furthermore, the process cartridge may contain at least the electrophotographic photosensitive drum and the developing means. The present invention is applicable to a process cartridge having developing means of such a structure.
Heretofore, in an electrophotographic image forming apparatus using the electrophotographic image process, a process-cartridge type, in which the electrophotographic photosensitive member and process means, actable on the electrophotographic photosensitive member, are integrally contained in a cartridge, which is detachably mountable to the main assembly of the image forming apparatus. Heretofore, in an electrophotographic image forming apparatus using the electrophotographic image process, a process cartridge type, in which the electrophotographic photosensitive member and process means, actable on the electrophotographic photosensitive member, are integrally contained in a cartridge, which is detachably mountable to the main assembly of the image forming apparatus.
Such a process cartridge contains a photosensitive drum, and developing means is used to apply the developer (toner) to the latent image formed on the photosensitive drum. In the developing means, a developing device frame supporting a developing roller for feeding the toner to the photosensitive drum and a toner frame (toner container) accommodating the toner, are coupled with each other. Before the start of use of the process cartridge, the opening provided in the connecting portion between the toner frame and the developing device frame are sealed by a seal member. A process cartridge equipped with an automatic toner seal removing device for automatically unsealing the opening of the toner frame when the process cartridge is mounted to the main assembly of the image forming apparatus, and an image forming apparatus, which is capable of driving the automatic toner seal winding device, are known.
The present invention provides a further development.
It is a principal object of the present invention to provide a developing cartridge, a process cartridge, and an image forming apparatus to which the process cartridge is mountable.
According to an aspect of the present invention, there is provided a process cartridge detachably mountable to a main assembly of an image forming apparatus, comprising: an electrophotographic photosensitive member; developing means for developing an electrostatic latent image formed on the electrophotographic photosensitive member with a developer; a developer container for containing the developer, the developer container having an opening for supplying the developer to the developing means; a sealing member for sealing the opening of the developer container; a winding shaft for winding the sealing member, the sealing member being rotatably supported by the developer container; driving means for applying a driving force to rotate the winding shaft; and drive control means for permitting and preventing transmission of the driving force to the winding shaft, wherein the driving control means permits the transmission in response to insertion of the process cartridge into the main assembly of the image forming apparatus and prevents transmission in response to a predetermined number of rotations of the winding shaft.
According to another aspect of the present invention, there is provided an electrophotographic image forming apparatus for forming an image on a recording material, to which a process cartridge is detachably mountable, the apparatus comprising: a. mounting means for detachably mounting the process cartridge, the process cartridge including: an electrophotographic photosensitive member; developing means for developing an electrostatic latent image formed on the electrophotographic photosensitive member with a developer; a developer container for containing the developer, the developer container having an opening for supplying the developer to the developing means; a sealing member for sealing the opening of the developer container; a winding shaft for winding the sealing member, the sealing member being rotatably supported by the developer container; driving means for applying a driving force to rotate the winding shaft; and drive control means for permitting and preventing transmission of the driving force to the winding shaft, wherein the driving control means permits the transmission in response to insertion of the process cartridge into the main assembly of the image forming apparatus and prevents transmission in response to a predetermined number of rotations of the winding shaft; b. feeding means for feeding the recording material; and c. driving means for driving the driving means of the process cartridge.
According to a further aspect of the present invention, there is provided a process cartridge detachably mountable to a main assembly of an image forming apparatus, comprising: developing means for developing an electrostatic latent image formed on an electrophotographic photosensitive member with a developer; a developer container for containing the developer, the developer container having an opening for supplying the developer to the developing means; a sealing member for sealing the opening of the developer container; a winding shaft for winding the sealing member, the sealing member being rotatably supported by the developer container; driving means for applying a driving force to rotate the winding shaft; and drive control means for permitting and preventing transmission of the driving force to the winding shaft, wherein the driving control means permits the transmission in response to insertion of the developing cartridge into the main assembly of the image forming apparatus and prevents transmission in response to a predetermined number of rotations of the winding shaft.
According to a further aspect of the present invention there is provided an electrophotographic image forming apparatus for forming an image on a recording material, to which a developing cartridge is detachably mountable, comprising: a. mounting means for detachably mounting the process cartridge, the process cartridge including: developing means for developing a latent image formed on an electrophotographic photosensitive member with a developer; a developer container for containing the developer, the developer container having an opening for supplying the developer to the developing means; a sealing member for sealing the opening of the developer container; a winding shaft for winding the sealing member, the sealing member being rotatably supported by the developer container; driving means for applying a driving force to rotate the winding shaft; and drive control means for permitting and preventing transmission of the driving force to the winding shaft, wherein the driving control means permits the transmission in response to insertion of the developing cartridge into the main assembly of the image forming apparatus and prevents transmission in response to a predetermined number of rotations of the winding shaft; b. feeding means for feeding the recording material; and c. driving means for driving the driving means of the process cartridge.
According to the present invention, it is not until the process cartridge is inserted into the image forming apparatus that drive transmission from the driving means to the winding-up shaft is permitted, and therefore, even if driving means is actuated for the purpose of inspection during the assembling of the process cartridge, the seal member is not unintentionally wound up. When the winding-up shaft rotates through a predetermined number of turns, the winding-up shaft is released from the driving, and therefore, the winding-up shaft is not driven after the sealing member is wound up. Thus, it can be avoided that an end portion of the seal member flappers with the result of toner scattering and/or different sound or the like. Additionally, the load of the driving source of the main assembly of the image forming apparatus can be reduced.
These and other objects, features and advantages of the present invention will become more apparent upon a consideration of the following description of the preferred embodiments of the present invention taken in conjunction with the accompanying drawings.